Method: (GC-WORK-FOR-SIZE HEAP T)

Source

(defmethod gc-work-for-size ((heap heap) size)
  ;; The garbage collector needs to be ready when there's no more free space
  ;; left in the heap. So when SIZE octets are allocated, the garbage collector
  ;; needs to collect a proportional amount of bytes:
  ;;
  ;;     Size / Free = Work / WorkLeft
  ;;
  ;; or: Work = (Size / Free) * WorkLeft
  ;;
  (if (zerop size)
      0
    (let* ((free (free-space heap))
           (work-left (work-left heap)))
      (if (>= size free)
          work-left
        (floor (* size work-left) free)))))